Synthetic Blood Is Flawed

June 26, 1986|By Jon Van, Science writer.

Fluosol, a synthetic substitute for human blood, is inadequate for patients who need transfusions during surgery, researchers from Chicago`s Michael Reese Medical Center reported in Thursday`s New England Journal of Medicine.

The team, led by Dr. Steven A. Gould, evaluated the outcome of 23 surgical patients at Reese who had religious objections to receiving transfusions of human blood.

In that group, eight were judged to be in need of transfusions and were given Fluosol. Six of those patients died and one of the two survivors was given natural red blood cells, against his wishes, under a court order, as well as the synthetic product.

Of the 15 patients who lost moderate amounts of blood and weren`t given transfusions, 14 survived.

The Reese team concluded that Fluosol didn`t carry enough oxygen to the patients` tissue to sustain life in most cases and that its actions didn`t last long enough for the patients` bodies to regenerate their own red blood cells.

``Fluorocarbons are excellent oxygen carriers,`` Gould said in an interview Wednesday, ``but the Fluosol emulsion was only 20 percent fluorocarbon, and what you were able to get into the patients was only about 5 percent.``

Dilution was necessary because fluorocarbons are soluble in water, Gould noted.

Although Fluosol failed in the Reese study to show benefits when used in transfusion, the study produced a secondary finding. The Reese team found that in general surgery patients may not need transfusions of blood as often as traditional practice assumed.

Because of the experimental nature of Fluosol, the surgeons monitored patients closely and didn`t order transfusions for the patients with moderate blood loss. Gould said that result may lead to future studies to assess how much blood a patient can lose before a transfusions is necessary.

Since AIDS, the fatal acquired immune deficiency syndrome, may be spread through blood transfusions, physicians and their patients have begun to rethink traditional assumptions about transfusions.

Fluosol may still find a medical use, Gould said. Other researchers are studying its effectiveness in helping patients whose coronary arteries are unblocked by a balloon inserted and inflated at the point of blockage.

In that procedure, called angioplasty, the inflated balloon itself blocks blood flow to heart tissue as the balloon is inflated to open the artery walls.